The routines IKJEFTSI and IKJEFTST set up and terminate, respectively, a specified command/program invocation platform. Routine IKJEFTSR allows eligible commands and programs to run on that platform.

Eligible commands and programs are those having an entry in SYS1.PARMLIB, member IKJTSOxx. Commands and programs are specified in this member using the PLATCMD and PLATPGM statements, respectively. Installations can add their own commands and programs to the appropriate platform statement, but they must first ensure that these commands and programs do not require the services of MVS™ task termination. If an application program terminates before the environment created by IKJEFTSI terminates, a system abend A03 can result. For more information about PLATCMD, PLATPGM, SYS1.PARMLIB, and about adding installation-defined commands and programs, see z/OS TSO/E Customization.

The following three sections describe how the TSO/E Service Facility routines interact with each other and with the application program using them. Refer also to Figure 1.

Figure 1. Interaction of the TSO/E Service Facility Routines